<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <script>
    var num = 123
    console.log(window)
    console.log(Number.MAX_VALUE)
    console.log(Number.MIN_VALUE)
    // integer: 整数
    console.log(Number.MAX_SAFE_INTEGER)
    console.log(Number.MIN_SAFE_INTEGER)
    // 对象的方法
    var num = 1000
    console.log(num)
    console.log(typeof num.toString())
    console.log(num.toString(2)) // 2进制
    console.log(num.toString(8)) // 8进制

    console.log(123..toString(2))

    var pi = 3.1415926
    console.log(pi.toFixed(2))
    console.log(pi.toFixed(3))
    console.log(123..toFixed(2))

    var num1 = "123.521"
    console.log(Number(num1))
    console.log(Number.parseInt(num1)) //123
    console.log(Number.parseFloat(num1)) //123.521
    console.log(parseInt(num1))
    console.log(parseFloat(num1))

    console.log(window.parseInt === Number.parseInt)


  </script>
</body>

</html>